Stamping machines



April 14, 1964 HENNEQUIN 3,128,698

STAMPING MACHINES Filed Feb. 2; 1961 4 Sheets-Sheet 1 FIG. 2

71 4f 33 E s2 11 l V V April 14, 1964 M. HENNEQUIN STAMPING MACHINES 4 Sheets-Sheet 2 Filed Feb. 23, 1961 April 14, 1964 M. HENNEQUIN 3,128,698

STAMPING MACHINES Filed Feb. 23, 1961 4 Sheets-Sheet 5 A ril 14, 1964 M. HENNEQUIN 3,128,698

I STAMPING MACHINES Filed Feb. 23, 1961 4 Sheets-Sheet 4 lllI/ll/ll/ United States Patent This invention relates to letter stamping machines, and more especially though not exclusively to stamping machines of the type including a separate tamper-proof attachment in which the sum total of equal postage fees stamped on a series of letters at a stamping station of the machine is adapted to be automatically registered.

A broad object of the invention is to provide an improved letter stamping machine in which the rate of stamping operations may be considerably increased over what is possible in conventional machines. To attain such an object it is, of course, not suflicient merely to increase the rate at which a series of letters can be individually fed past the stamping station, unless the stamping or printing mechanism provided at said station is itself capable of positively and reliably stamping each of the letters fed past it at the increased rate.

One reason that has heretofore limited the rate at which the printing mechanism of a stamping machine could operate successfully, is the comparatively large diameter of the printing cylinders that have been required. The printed matter that is required to be stamped on a letter generally includes at least two, and often more items: one of these items of course is the postage fee, while another usually includes the datemark. Usually, the type comprising both the postage and the daternark information has been provided in the form of separate printing elements or blocks around the circumference of a common piinting cylinder mounted for rotation about an axis transverse to the path of feed of the letters past the printing station; an additional segment of the cylinder periphery had to be kept blank to allow for insertion of the letters under the cylinder. In view of these requirements the circumference and diameter of the printing cylinder used were large, its developed circumferential length being usually longer than the length of the letters to be stamped. This in turn has entailed the unavoidable presence of a considerable idle space from the trailing edge of each previously stamped letter to the leading edge of the next, with a corresponding idle period during which the rotation of the printing cylinder had to be arrested between two successive revolutions.

A specific object of the invention, then, is to reduce the diameter of the printing cylinder means required to stamp prescribed information on letters fed past it and thereby to increase the stamping rate. This object is attained by providing at the printing station two printing cylinders instead of one, so that the diameter of each cylinder can be correspondingly reduced.

The invention (in this aspect) therefore comprises a letter stamping machine which comprises means for feeding letters serially past a printing station, a first and a second printing cylinder at said station longitudinally spaced along said path and rotatable about axes transverse to it, type indicative of a postage fee on the periphery of one cylinder and type indicative of other matter, e.g. a datemark, on the periphery of the other cylinder, and drive means for rotating both cylinders to print the related indications on each of a series of letters fed therepast.

Further to increase the operating rate and reliability, the printing cylinders are preferably arranged to be rotated (for one revolution) from permanently revolving power means, through friction coupling means or the like, automatically in response to the approach of each letter towards the printing station as sensed by a suitable feeler 3,128,698 Patented Apr. 14, 1964 element, thereby reducing inertia effects at the start and end of each printing operation. According to a related feature, improved inking means are preferably provided which are operated in synchronism with the rotation of the printing cylinders to transfer metered amounts of ink to the printing cylinders at each revolution of them.

In a preferred embodiment of the invention, as earlier mentioned, the machine embodies a separate attachment which contains counter means adapted to register the sum total of equal postage fees stamped on a series of letters, and which is tamper-pro0f, yet relatively small and light weight; such an attachment may incorporate at least the postage-fee printing cylinder therein, together with means whereby such cylinder will automatically be inserted into operative driven relationship at the printing station of the stationary section of the machine, on engagement of the register attachment with the stationary section.

Other objects lie in the provision of improved safety means and/ or interlocks for enhancing the reliability of stamping operations, as by positively preventing the stamping of the same information on one and the same letter, and preventing a letter from being stamped until it has attained its prescribed position at the printing or stamping station. It is also an object to provide an improved letter feeding arrangement in a stamping machine.

The objects, features and advantages of the invention will be made clear from the ensuing disclosure of a preferred embodiment thereof given by way of illustration but not of limitation with reference to the accompanying drawings, wherein:

FIG. 1 is an exemplary and diagrammatic view of various items of printed matter to be stamped on each letter with the machine of the invention;

FIG. 2 is a simplified side elevational view of the stamping machine;

FIG. 3 is a corresponding view in plan;

FIG. 4 is a simplified view in side elevation, on a scale enlarged over that of FIGS. 2 and 3, illustrating the let-- ter-feeding and -spacing means and the stamping station of the machine together with related mechanism;

FIG. 5 is a partial section on line V-V of FIG. 4;

FIG. 6 shows the inking mechanism on a further enlarged scale;

FIG. 7 is a partial section on line VII-VII of FIG. 6;

FIG. 8 is a perspective view showing the supporting arrangement for an inking roller and cylinder;

FIG. 9 illustrates an additional latching mechanism optionally used;

FIG. 10 schematically illustrates an interlock arrange ment; and

FIG. 11 is a perspective view of the separable register attachment with the counter mechanism contained therein, and also shows the cooperating means for engaging said attachment with the stationary section of the machine.

The embodiment of the invention to be described serves to impress upon the envelopes to be stamped (such as 1, FIG. 1), a number of diiferent marks or imprints as schematically indicated by way of example in FIG. 1, viz.: a postage fee stamp 2, a datemark 3, as well as various optional markings such as a corporate name orv seal at and advertising text or other matter at 5.

The machine illustrated generally in FIGS. 2 and 3 comprises a frame including a baseplate 11 having a vertical wall 12 upstanding from it substantially along a central longitudinal plane of the generally rectangular baseplate. Projecting from one side of the vertical wall 12 is a horizontal shelf or table 13 spaced above the baseplate 11. The other side of wall 12 serves to support a number of mechanical components to be later described, all of which mechanism is covered by a hood 14 having edges removably secured to the baseplate and the vertical wall 12.

A batch of letters to be stamped is adapted to be placed in a stack 21 (also see FIG. 4) upon the upper surface of an endless feeder belt 22 which is so supported from the frame wall 12 that the upper leaf surface of the belt lies substantially flush with the upper surface of the shelf 13. The belt is driven through means to be described so that its upper run is advanced in a horizontal direction parallel to the vertical plane of wall 12 as indicated by arrow f1 in FIGS. 3 and 4. The belt 22 is trained around a freely rotatable pulley 23 at one end and a drive pulley 24 at its other end both pulleys mounted on shafts supported from wall 12. The drive pulley 24 has a gear 25 coaxially secured to it which meshes with a gear 26 carried on a drive shaft 27 driven from any suitable source of power, not shown, preferably an electric motor.

The stack of letters 21 piled on the upper run of belt is retained against lateral displacement on one side by the adjacent surface of vertical wall 12, and on the other side by a bent guide rod 31 having one end secured in a support 32 which is provided with a blocking screw 33 for adjusting the position of the guide rod in accordance with the over-all width dimension (normally to the projection plane of FIG. 2) of the stack of letters being handled.

The leading end of the stack 21, in the direction of feed of feeder belt 22, is abutted against a vertical plate element 35 which has its lower end spaced somewhat above the upper surface of belt 22 and a strip 36 of flexible material such as rubber projecting from said lower end of the plate into frictional engagement with the belt surface as shown in FIG. 4. In this way only the lowermost letter positioned at any time in the stack 21 is allowed to be discharged from the belt 22 while the overlying letters are retained by the strip 36, and the letters thus issue one by one from the front end of feeder belt 22.

Positioned beyond and in alignment with the feeder belt 22 is another endless belt device 38 which may be termed the spacer belt for reasons that will presently appear. Belt 38 is mounted around the two end pulleys 39 and 41, pulley 39 being freely rotatable and drive pulley 41 being secured to a coaxial gear 42 which is driven from the same drive gear 26 as that driving the gear 25 of feed belt 22, but gear 42 being smaller in radius than gear 25 so that the linear velocity of the spacer belt 38 is substantially higher than the linear velocity of feeder belt 22. In this way each letter as it is discharged from the front end of feed belt 22, and taken up by the spacer belt 38, is subjected to a sudden acceleration and as a result the letters advance upon the upper surface of belt 38 in a longitudinally spaced array. Such spacing between the adjacent letters is necessary for the proper operation of the printing mechanism now to be described, and towards which the letters are advanced by the spacer belt 38.

The printing means include two separate printing cylinders 45, 46, also suitably supported from frame wall 12. Each printing cylinder 45, 46 carries a printing element or block 45a, 46a respectively, extending over part of its periphery as illustrated in FIG. 6. Printing block 45a carries a print of the postage stamp 2 (and optionally other markings such as the corporate name or seal 4 as previously indicated), while printing block 46a carries the datemark 3 (and optionally other markings such as the advertising matter 5).

The printing cylinders 45, 46 are driven in synchronism with one another from a shaft 47 journalled in frame wall 12, through gearing including gear 48 secured on shaft 47 and gears 51, 52 respectively secured to the printing cylinders 45, 46.

Means are provided for resiliently pressing upwardly the upper run of spacer belt 38 against the under surface of each printing cylinder 45, 46, and these means comprise as shown the two similar pivoted presser roller assemblies including the arms 56 or 57 pivoted on the fixed pivots 58, 59 and biassed by springs 61, 62 in a direction to move rollers 54, carried at the ends of said arms into engagement with the underside of the upper leaf of belt 38 in substantially tangent relation with the respective drums 45, 46 at the lowermost points thereof. The printing cylinder drive shaft 47 is driven from the afore-mentioned electric motor or other central power source through a friction coupling, not shown. Shaft 47 may be termed the primary drive shaft of the machine.

FIG. 6 illustrates inking mechanism for the printing cylinders. In this figure the cylinders are shown in the positions assumed by them in the so-called waiting position after having completed one intermittent revolution as later described. In this position the printing elements 45a, 46a are positioned clear of the surface of belt 38 shortly after having swept said surface on rotation of the cylinders 45, 46 in the counterclockwise directions of the arcuate arrows shown. A pair of inking rollers 65, 66 are mounted adjacent the respective printing cylinders 45, 46 so as to be clear of the printing elements 45a, 46a thereof in this waiting position of the cylinders. The inking rollers may be lined with felt or similar absorbent lining and are arranged to be in permanent surface engagement with respective inking cylinders 67, 68 which may be made of steel or other material and are permanently rotated from the central drive motor through means not shown. As will later appear, the inking rollers 65, 66 in contrast are only rotated intermittently one revolution every time a letter is passed through the printing mechanism.

Mounted above the inking cylinders 67, 68 is an ink reservoir-and-feeder unit 71. The upper part of unit 71 is recessed to provide an ink reservoir 72 and this communicates through the ducts 73, 74 respectively with two bores formed in the body of unit 71 in which bores a pair of similar cylindrical distributor cores 75, 76 are rotatable. Each distributor core has an axial groove 79, 79 formed in its periphery. Further ducts 77, 78 connect the respective distributor bores with the spaced bottom outlets of the inking structure 71 which deliver adjacent to the upper part of the peripheral surfaces of inking cylinders 67, 68. The distributor cores 75, 76 are driven in rotation through gears 81, 83 secured to the respective cores and meshing with a common drive gear 82 which, through an intermittent drive connection not shown, is adapted to have one revolution imparted to it from primary drive shaft 47 every time a letter is passed through the printing mechanism. In this way a metered amount of ink from reservoir 72 is transferred by means of the grooves 79 in distributor cores 75, 76 to each of the ducts 77, 78 for delivery to the surface of the continuously revolving inking cylinders 67, 68.

Both felt-lined inking rollers 65, 66 are mounted by way of similar means arranged to impart suitable drive thereto and also to permit of adjusting the rollers for wear compensation. FIG. 8 illustrates the arrangement relating to inking roller 66. As shown the inking roller is journalled across the ends of a two-armed clevis member 85 which is pivotable about a shaft 86 carried at one end of a bell-crank lever 87 which in turn is pivoted around a shaft 88 which carries the relating inking cylinder 68. A spring 91 biasses the clevis support 85 in a direction to apply the roller 66 against inking cylinder 63, while another spring 92 biasses the lever 87 so as to swing the assembly bodily in a direction to apply the inking roller 66 against the printing cylinder 46. An adjustable stop screw 94 limits the rotation of the assembly about the shaft 88 under the influence of spring 92 so that the felt lined inking roller 66, will only engage the larger-radius surface of printing element 46a but not the smaller-radius remaining surface of the printing cylin der 46 during rotation of the latter.

Rotation of the shaft 47 driving the printing cylinders is arrested, as permitted by the frictional character of the drive coupling thereof (not shown), for so long as no letter is passing through the printing mechanism, by means of a swingable member or pawl 101 (see FIGS. 4 and 9) adapted to engage a nose 102 projecting radially from the primary shaft 47. Latch 101 is pivoted on a fixed pivot 103 and is connected by a link 104 with a further lever arm 1135 having its lower end pivoted at 106 to the frame and its other end having a projection applied by a biassing spring 107 attached to arm 105 into engagement with a latching cam 108 secured on a secondary shaft 109 driven from the central drive motor of the machine through a friction clutch. The secondary shaft 109 (or cam 108) has a projection 111 engageable by one end of a bellcrank lever 112 pivoted to the frame and biassed by a spring 113 for engagement of the tip of lever arm 112a intothe rotational path of projection 111. The other arm 112]) of the bellcrank lever 112 is connected by a link 115 to a lever 116 pivoted at an intermediate point of its length on a pivot 117 carried by one end of a further lever 118 having its other end pivoted at 119 to the frame. The lever 116 has a crooked arm extending from its lower end and having an extremity or finger 122 projecting somewhat below the plane on which the letters are travelling over the upper surface of belt 38. For this purpose the belt 38 is actually constituted as two parallel transversely spaced belt portions 38a and 381) (FIG. 5) and the finger 122 projects into the space therebetween in such a way as to be actuated by the leading edge of a letter issuing from the first feeder belt 22.

Lever 118 is biased in a clockwise direction by gravity aided by a spring 123 and its rotation in that direction is limited by a stop 124 which thus serves to determine with accuracy the vertical position of the finger 122.

It will be understood that the mechanism just described serves to cause the printing cylinders to be rotated one revolution every time a letter is passed through the machine as will be explained in fuller details later. To ensure that the finger 122 shall be positively actuated by the leading edge of an advancing letter, it will be noted that said finger is positioned susbstantially above and in vertical alignment with the axis of the drive pulley 41 of the belt 38 and a presser roller 125 is carried by a pivoted arm 127 biassed counterclockwise by a spring 126 so as to press the letters firmly against the belt surface.

In the embodiment shown the datemark printing cylin der 46 is fixedly mounted on the machine frame. The stamp printing cylinder 45 on the other hand is supported from a stamping register assembly or counter 129 (see FIGS. 2, 3 and 11) which is arranged as a separate unit or attachment removably connectable with the machine frame. Referring to the perspective view of FIG. 11 which illustrates the stamp register attachment in detail, it will be seen that the stamp printing cylinder 45 is secured on a shaft 131 which is journalled in the frame 132 of said register. The register frame 132 is attachable to the general frame of the machine by means of a tubular sleeve 130 extending through the register frame 132 and insertable around a specially shaped spindle 136 fixedly projecting from the upstanding frame wall 12. The register frame is blocked against rotation on spindle 136 by means of a pin 137 projecting from the Wall 12 in parallel spaced relation to spindle 136 and insertable into a corresponding hole in register frame 132, and said register frame is blocked against axial displacement on spindle 136 by means of a latch arm 13? pivoted on a shaft 165 of frame 132 and engageable in a transverse notch 139 formed in the mounting spindle 136 as will be more fully explained.

With the register attachment mounted on the machine frame in the manner just described, the stamp printing cylinder 45 is adapted to be driven from the drive mechanism of the machine by way of gear 51 as earlier indicated. While in the earlier description gear 51 was considered to be coaxially secured with the cylinder 45, this is not actually the case in the exemplary embodiment now being described. In fact, gear 51 is secured on a shaft 134 journalled in the frame wall 12 and driven from the general drive of the machine. Shaft 134 carries an asymmetrically shaped radial driver element 133 which, in the mounted condition of the register attachment, engages with a complementary radial notch formed in the stamp printing cylinder 45.

The stamp register mechanism will now be described. Removably secured on shaft 131 for rotation therewith are two axially spaced gear sectors 141, 142. Assuming for descriptive purposes that the postage fee to be stamped is 25 monetary units (e.g. centimes), the gear sectors 141 and 142 are respectively provided with two and five teeth. Secured on the afore-mentioned shaft 165 of the register frame are two pinions 143, 144 positioned for meshing engagement with the sectors 141, 142 respectively, and the pinions 143, 144 in turn are in meshing engagement with respective gears 145, 146 rotatably mounted on another shaft of the register attachment. Gear 145 has integrally secured to it a tens counter wheel 147 and gear 146 has integrally secured to it a units counter wheel 148, each counter wheel being marked with the digits 0 through 9 around its periphery as shown. Rotatably mounted on the counter shaft in alignment with the counter wheels 147 and 148 are further counter wheels and attached gears, including a hundreds counter wheel 151 and a thousands counter wheel 152, additional counter wheels and attached gears being provided if desired. For the transfer of carries from one counter gear to the next, there are provided in the conventional manner the carry transfer pinions 153, 154, which are mounted on a shaft 155 of the register frame for automatically effecting transfer of carries from the tens to the hundreds digital positions and from the hundreds to the thousands positions respectively, every time the counter wheel of the lower digital position has completed a revolution, in a manner well-known in mechanical counter machinery.

Except during the periods where the gear teeth of sectors 141 and 142 are in engagement with the related intermediate gears 143, 144 for advancing the related counter wheels, said counter wheels are latched against rotation thereby preventing rotation of the wheels by inertia. The latching means for this purpose comprise latch pawls 157, 158 respectively, pivoted about shaft and cooperating with cams 161, 162 secured on shaft 131. The pawls 157, 158 are biassed by springs 163, 164 in a direction to engage the related counter wheels and thereby block them against rotation, while the cams 161, 162 act to disengage the pawls against their spring bias to release the counter wheels during the appropriate periods of the rotation of shaft 131.

Transfer of carries from the units to the tens Wheel is provided for by means of a cam 167 secured on shaft 131 and cooperating with an intermittent drive arrange ment comprising two axially juxtaposed elements 168a and 1691) freely rotatable as a unit around shaft 165 and each in the form of a four-branched star in angularlydisplaced relation with each other to constitute a kind of dual Maltese cross arrangement. The star element 168a cooperates directly with a cutout 169 in cam 167 while element 168!) cooperates with a projection 171 of the units counter wheel 148. i

The units carry transfer system thus described is of a well-known type and operates as follows. As the units counter wheel 148 is shifted from the 9 to the 0 digital position, the projection 171 actuates a point of the starshaped element 168!) to a position in which the other star element 168a presents one of its points to the cutout 169 of cam 167 which in turn actuates said lastnamed point so that the opposite point of element 168a engages and actuates one of a set of teeth 172 formed on one side of the tens wheel 147, thereby advancing said wheel by one digital increment or step. To permit this movement it is obviously necessary that the latch pawl 157 has released the gear 145 secured to the tens wheel; to ensure this efiect the earn 161 is provided with a cutout as shown. The timing of the system is such that the 7 carry transfer operation is effected after the units and tens digits have been registered.

The counter-and-register attachment described further includes means for preventing unauthorized tampering as well as for reducing likelihood of error in use.

The tamper-proofing means are intended to prevent manipulation of the register attachment after the attachment has been separated from the machine. For this purpose the shaft 131 carries a ratchet wheel 175 cooperating with a pawl 176 pivoted on shaft 165 and biassed into engagement with the ratchet by a spring 177, thereby preventing reverse operation of the counter, as for deliberately reducing the sum total of registered postage fees. To prevent unauthorized rotation of the counter when the attachment is separated from the machine with the object of rotating it past its zero or reset condition for a similar unauthorized purpose, the shaft 131 carries another cam 181 formed with a notch 182 adapted to engage with a roller 183 carried by an extension of lever 138 and biassed into engagement with the cam 181 by a spring 184 so as to engage said cutout therein in the waiting or ready position. Thus, with the attachment removed from the machine, should it be attempted to rotate shaft 131 in the normal or forward direction, the roller 183 would be actuated by cam 181 and would tend to cause a rotation of lever 138, but such rotation is then prevented by the action of a bent arm 138a extending from lever 138 and adapted to engage an arm 186a of a blocking bellcrank lever 186 mounted on the shift pinion shaft 155, the other arm 186 b of which lever engages a transverse slot 188 formed in the sleeve 130 serving to mount and guide the attachment with respect to the machine frame. A spring 189 biasses lever 186 to its locking position. At the time the counter attachment is positioned on the machine frame, an incline 191 formed near the outer end of mounting spindle 136 actuates the lever arm 186b and displaces it thereby to rotate the bellcrank lever 186 and its other arm 186a is thus moved clear of the path of arm 138a of locking lever 138. Thus the stamping mechanism is now rendered operable in the forward or normal direction.

As a further precautionary measure, matters are so arranged that with the shaft 131 in its waiting or ready position which it necessarily assumes when the counter attachment is removed from the machine, the printing element 45a is inaccessible from the exterior, i.e. the printing cylinder 45 is at a tamper-proof angular position.

Means are provided for positively preventing the counter from exceeding its maximum capacity in normal operation since otherwise it would again start counting from zero. For this purpose the highest-order digital counter wheel, in this instance the thousands wheel 152, has a cam 191 integral with it, the cam being formed with a notch 192 so positioned that as the said thousands wheel is shifted from the 9 to the position, the free end of one arm of a U-shaped lever 193 pivoted on shaft 1'55 and biassed by a spring 194 into engagement with the cam, engages the cam recess 192, at which time the other arm of the U-shaped lever is displaced into the path of movement of the afore-mentioned locking lever arm 138a. In this condition the totalizing counter or register mechanism is therefore blocked and the postageprinting cylinder is prevented from rotation. Damage to the mechanical parts in this condition is prevented by the provision of the friction clutch previously referred to.

Means are further provided to prevent operation of any part of the machine unless the register attachment is correctly positioned thereon. For this purpose the mounting spindle 136 has a plunger rod 198 slidable in a bore of the spindle and having a stop 199 projecting from the rod 198 through a longitudinal slot 201 in a side of the mounting spindle, so as to be actuated by the frame of the register attachment when the latter is inserted in position around spindle 136 as earlier described. When the stop 199* is moved to its rearward end position as the register frame 132 is pushed home, the free end of rod 198 actuates a contact plunger 197 projecting from a switch 196 suitably mounted on the machine frame and electrically connected in the energizing circuit of the motor (not shown) which provides the central drive for the machine assembly.

Summarizing the general operation of the machine, a mobile counter 129 in which the printing block element 45a is marked with appropriate postage value and the gear sectors 141, 142 are correspondingly selected, is bodily mounted on the machine frame by inserting it around the spindle 136. Then a stack 21 of letters to be cancelled is placed on the table 13 of the machine the letters being all oriented in a common and appropriate position to receive the cancelling marks in an appropriate corner of each of them. The machine is started in operation by actuating a starting switch 235 (FIG. 3) to energize the drive motor, or by engaging a clutch. Now the bottommost letter of the stack 21 is driven by feeder belt 22 in the direction shown by arrow f1 while the overlying letters are prevented from advancing by the rubber strip 36 and wall 35. Said bottom letter is transferred to the spacer belt 38 and as explained the higher linear velocity of belt 38 over that of belt 22 acts to displace the letters one by one into a spaced array. As each letter is transferred from belt 22 to belt 38 its leading edge actuates the finger 122 which rotates lever 116 counterclockwise (arrow f2). Link 115 is thus pulled leftward (as shown in FIG. 4) and rotates lever 112 as indicated by arrow f3. The arm 112a of lever 112 is raised and releases projection 111 of cam-shaft 109, permitting rotation of the shaft. Cam 108 secured to said shaft thereafter rocks lever rightward and said lever thereupon acts through link 104 to swing member 101 as shown by arrow 14, releasing the latching projection 102 of shaft 47. Shaft 47 is now permitted to rotate and imparts one revolution to the printing drums 45 and 46 as well as the inking cylinders 67, 68 to impress the desired markings on the letter positioned under the printing cylinders. At the same time one revolution is imparted to the register drive shaft 13 1, thereby registering the postage fee value just printed, and correspondingly increasing the sum total value indicated by the counter Wheels 148, 147, 151, 152.

It should be noted that after the foremost letter has actuated finger 122 on being transferred to belt 38, said finger 122 is promptly restored by the biassing action of spring 113 acting through linkage 112, 115, 116, to a position in which the tip of finger 122 is resting on the upper surface of the letter passing under it, instead of said finger 122 penetrating into the space between belt elements 33a, 38b as is the case in the absence of a letter. Hence, the arm 112a of lever 112 has been restored into the path of travel of the nose 111 projecting from shaft 109 and said shaft will be arrested after having completed one revolution.

The swingable member 101 is returned to its latching position immediately after actuation of the printing device, so that no matter how long the letter just stamped may be, there is no risk of the same letter being stamped twice since member 101 is shifted to latching position as soon as the printing device is started in operation, and since said pawl cannot be unlatched from that position so long as shaft 109 does not have another revolution imparted to it; this however can only occur on the finger 122 being actuated by the leading edge of the next letter of the series as such next letter is transferred from belt 22 to belt 38. This is true because it is only after a letter has moved completely past the finger 122 that said finger is enabled to move down by the action of spring 123.

The embodiment described may further desirably include means for preventing premature printing, i.e. before a letter has effectively reached its correct position at the printing station. The means, shown in FIG. 9, comprises a nose 205 projecting from printing drive shaft 47, and

adapted for latching engagement by a latching pawl 206 pivoted about a fixed shaft 207, said pawl having an extension 208 which normally projects into the path of the letters between the two belt elements 38a, 38b. Pawl 206 is biassed by a spring 209 towards shaft 47. It will be apparent that with this arrangement the printing means cannot be actuated unless both projections 102 and 205 have been released by their related pawls under the combined actions of finger 122 and finger 208, as said fingers are successively displaced by the leading edge of an advancing letter. When projection 102 is engaging member 101 a certain amount of clearance is present between projection 205 and pawl 206.

Thus, in normal operation the leading edge of a letter actuates finger 208 to release pawl 206 before member 101 has been disengaged from projection 102 and has released shaft 47. However, should for example the finger 122 be accidentally retained due to frictional contact with belt 38, or should a letter become jammed and its progress arrested after its leading edge has actuated finger 122, then the finger 208 will not be actuated by the letter and pawl 206 will remain in engagement with projection 205, so that as the swingable member 101 releases projection 102 in response to the actuation of finger 122, the printing device remains inoperative.

FIG. illustrates a further optional safety device serving to avert the objectionable consequences that would otherwise arise due to breakage or damage of the pawls and/ or springs, which would be liable to result in irregular stamping operations. The device shown constitutes an interlock means between primary shaft 47 and secondary shaft 109, and comprises a lever 211 pivoted at an intermediate point on a fixed pivot 212 and having one end formed as a pawl or hook 213 engageable with a stop 214 of shaft 109, while its other end has a rounded nose 216 cooperating with a cam 217 secured on shaft 47. Lever 211 is biassed by a spring 218 in a direction to disengage pawl 213 from the projection 214 of shaft 109. The device includes a further lever 221 pivoted on a fixed intermediate pivot 222 and formed at one end with a pawl shaped projection 223 for engagement with a nose 224 carried by shaft 47, while its other end is formed with a rounded nose 226 cooperating with a cam 227 secured to shaft 109. Lever 221 is biassed by a spring 228 in the direction to disengage pawl 223 from nose 224 of shaft 47. With this arrangement it will be apparent that secondary shaft 109 cannot be rotated in response to the passing of a letter unless the primary shaft 47 has been restored to its waiting position, while on the other hand primary shaft 47 commanding the printing operations cannot rotate unless secondary shaft 109 has been moved away from its waiting position.

Turning to minor features of the embodiment described, it is noted that the register-counter unit is provided with a cover or hood 230 (see FIGS. 2 and 3) formed with a window 231 through which the registered total can be read. The hood 230 is normally sealed when in the users possession and when the register unit is presented to the postal authorities for payment of the postage fees registered therein, the postal ofiicial breaks open the seal, removes the hood 230, releases blocking lever 193 and resets the counter to zero, and then puts back the hood and apposes a new seal thereon.

Shown at 232 in FIG. 3 is a counter provided with reset means 234 serving to indicate the number of letters stamped, and switch 235 for starting the electric motor is also shown.

It will be apparent that a great many departures may be made from the single embodiment illustrated and described. Thus various of the features may be omitted or combined in a variety of ways, depending on the particular requirements. Thus, the datemark printing cylinder, instead of being mounted in the stationary part of the machine, might well be incorporated in the mobile counter together with the postage stamp printing cylinder. Also,

the mobile counter may be simplified by constructing it so as to indicate merely the number of revolutions effected by the printing cylinder or cylinders, i.e. the number of stamping operations performed, rather than including mechanism for totalizing the postage fee values in monetary units.

What is claimed is:

1. In a mail marking machine, the combination with two parallel rotary printing drums one of which is a stamp printing drum, conveyor means for advancing mail matter successively from a starting point towards and past said drums to receive impressions therefrom, a mobile counter carrying said one drum and operated from said one drum once for each rotation thereof, a first continu ously frictionally driven shaft positioned between said drums and having a driving connection with said drums for revolving them simultaneously, and arresting means including a swingable member for arresting said first shaft at each revolution thereof, of a trip mechanism comprising a second continuously frictionally driven shaft positioned between said starting point and said drums, a stop and a cam projecting from said second shaft, said cam being axially and circumferentially spaced from said stop, movable lock means cooperating with said stop and movable between a stop engaging position and a stop releasing position, resilient means for urging said lock means into said stop engaging position thereof, a trip finger at said starting point adapted to be engaged by the leading end of each successive mail matter, said trip finger being connected to said lock means to move the latter against the action of said resilient means to said stop releasing position as the trip finger is moved by said leading end, said resilient means being effective to move said lock means into said stop engaging position thereof as soon as said trip finger is disengaged from said leading end to thereby lock said second shaft against rotation when the same has made one revolution, and means operable by said cam after release of said second shaft to move said swingable member of the arresting means for the first shaft so as to release the same for one revolution.

2. In the machine claimed in claim 1, a store of ink, rotatable inking roller means positioned for transferring ink from said store to said respective printing cylinders, and means rotated in synchronism with said cylinders for rotating said inking roller means to transfer a metered amount of ink from said store to said printing cylinders.

3. In a mail marking machine, the combination with two parallel rotary printing drums one of which is a stamp printing drum, conveyor means for advancing mail matter successively from a starting point towards and past said drums to receive impressions therefrom simultaneously on difierent regions of the individual mail matter, a mobile counter carrying said one drum and bodily removable from and replaceable in the machine adjacent the other drum, said counter being operated from said one drum once for each rotation thereof, a first continuously frictionally driven shaft positioned between said drums and having a driving connection therewith for revolving them simultaneously, and releasable arresting means for arresting said first shaft at each revolution thereof, of a trip mechanism comprising a second continuously frictionally driven shaft positioned between said starting point and said drums, a stop and a cam projecting from said second shaft, said cam being axially and circumferentially spaced from said stop, a bell crank lever pivotable between an operative position in which one of its arms engages said stop and an inoperative position in which said one arm releases said stop, resilient means for urging said bell crank lever towards said 0perative position thereof, trip mechanism including a pivotally mounted trip lever having one of its ends positioned at least adjacent said starting point so as to be engage able by the leading end of each successive mail matter, a link connecting the other end of said trip lever with the other arm of said bell crank lever whereby to pivot said bell crank lever against the action of said resilient means into its inoperative position as said trip lever is pivoted by the leading end of an advancing mail matter from its initial rest position, said resilient means being effective upon disengagement of said one end of the trip lever from said leading end of an advancing mail matter to simultaneously return said bell crank lever into its operative position to stop the second shaft when the same has made one revolution and to return the trip lever into said initial position thereof, and means operable by said cam after release of said stop by said crank bell lever for releasing said arresting means for the first shaft each time said second shaft is caused to make one revolution for each mail matter passing said starting point.

4. A mail marking machine according to claim 3, in which said trip mechanism further comprises a swingable arm having one end articulated to a fixed point of the machine and its other end articulated to a point of said strip lever intermediate both ends thereof, a fixed abutment member positioned so as to support said swingable arm in a substantially horizontal position thereof, and a spring for urging said arm towards said abutment member.

5. In a machine as claimed in claim 3, mutual interlock means interconnecting said primary and secondary shafts.

6. In a machine as claimed in claim 3, additional latch means associated with said primary shaft to prevent rotation thereof, and an additional feeler element displaceable by a letter on reaching a prescribed position at said station for releasing said additional latch means.

References Cited in the file of this patent UNITED STATES PATENTS 1,273,793 Pitney July 23, 1918 1,370,668 Pitney Mar. 8, 1921 1,633,245 Eskholme June 21, 1927 1,647,560 Chisholm et a1 Nov. 1, 1927 1,954,367 Smith Apr. 10, 1934 1,955,066 Hiller Apr. 17, 1934 2,005,778 Finfrock June 25, 1935 2,377,523 Ryan et al June 5, 1945 2,389,551 Ryan Nov. 20, 1945 2,690,710 Aurbach Oct. 5, 1954 2,846,945 Uthenwoldt et a1 Aug. 12, 1958 2,976,803 Van Marle Mar. 28, 1961 

3. IN A MAIL MARKING MACHINE, THE COMBINATION WITH TWO PARALLEL ROTARY PRINTING DRUMS ONE OF WHICH IS A STAMP PRINTING DRUM, CONVEYOR MEANS FOR ADVANCING MAIL MATTER SUCCESSIVELY FROM A STARTING POINT TOWARDS AND PAST SAID DRUMS TO RECEIVE IMPRESSIONS THEREFROM SIMULTANEOUSLY ON DIFFERENT REGIONS OF THE INDIVIDUAL MAIL MATTER, A MOBILE COUNTER CARRYING SAID ONE DRUM AND BODILY REMOVABLE FROM AND REPLACEABLE IN THE MACHINE ADJACENT THE OTHER DRUM, SAID COUNTER BEING OPERATED FROM SAID ONE DRUM ONCE FOR EACH ROTATION THEREOF, A FIRST CONTINUOUSLY FRICTIONALLY DRIVEN SHAFT POSITIONED BETWEEN SAID DRUMS AND HAVING A DRIVING CONNECTION THEREWITH FOR REVOLVING THEM SIMULTANEOUSLY, AND RELEASABLE ARRESTING MEANS FOR ARRESTING SAID FIRST SHAFT AT EACH REVOLUTION THEREOF, OF A TRIP MECHANISM COMPRISING A SECOND CONTINUOUSLY FRICTIONALLY DRIVEN SHAFT POSITIONED BETWEEN SAID STARTING POINT AND SAID DRUMS, A STOP AND A CAM PROJECTING FROM SAID SECOND SHAFT, SAID CAM BEING AXIALLY AND CIRCUMFERENTIALLY SPACED FROM SAID STOP, A BELL CRANK LEVER PIVOTABLE BETWEEN AN OPERATIVE POSITION IN WHICH ONE OF ITS ARMS ENGAGES SAID STOP AND AN INOPERATIVE POSITION IN WHICH SAID ONE ARM RELEASES SAID STOP, RESILIENT MEANS FOR URGING SAID BELL CRANK LEVER TOWARDS SAID OPERATIVE POSITION THEREOF, TRIP MECHANISM INCLUDING A PIVOTALLY MOUNTED TRIP LEVER HAVING ONE OF ITS ENDS POSITIONED AT LEAST ADJACENT SAID STARTING POINT SO AS TO BE ENGAGE- 